Air Filter



FIG. 1 is a top perspective view of an air filter showing our new design;

FIG. 2 is a perspective view from the bottom;

FIG. 3 is a side elevational view, the other sides being identical to that shown;

FIG. 4 is an enlarged fragmentary cross-sectional view taken along line 4--4 of FIG. 3; and,

FIG. 5 is an enlarged fragmentary cross-sectional view taken along line 5--5 of FIG. 1. 

The ornamental design for an air filter, as shown and described. 